I'm sad to hear about your friend, but I'm glad to hear you haven't given up! Congrats on not giving up.

Most, not some people, just don't have the mental stamina to keep a physical fitness program going. I'm weird about mine, I use to take martial arts for years but injury stopped that, I don't workout with weights, I have a bear of time trying to do much needed core workouts, but I don't mind riding a bike. Some people will do all of that stuff with no problem, their dedicated to the extreme, I'm just not that extreme. The vast majority of people are like your friend they just don't want to be bothered and would rather eat for exercise! And most people, just like your friend, just quit, and not due to injury either, it was mental war that they lost to.

But you keep at it, don't get depressed because some friend didn't stay with it and feel what the heck I might as well stop too. Don't let your mind play games with you. Congrats for not giving up and keep at it, your body's well being will love you for it.